Eye safety - CL61

CL61 Installation Guide

Document code
Document type
User guide

This Vaisala Lidar Ceilometer CL61 is classified as a Class 1M optical device in accordance with International Standard IEC/EN 60825‑1:2014. Complies with 21 CFR 1040.10 and 1040.11 except for conformance with IEC 60825-1 ED. 3., as described in Laser Notice No. 56, dated May 8, 2019.

Table 1. Radiated pattern emitted from protective housing, from CL61 window
Property Value
Maximum pulse energy 4.7 μJ
Laser wavelength 910.55 nm typical
Peak power 40 W
Maximum average power 50 mW
Pulse duration 160 ns FWHM
Pulse frequency 9.5 kHz
Beam divergence ±0.2 mrad × ±0.35 mrad

The following table describes the properties of the sole transmitter module. CL61 must never be operated and have power on when the transmitter module is not attached to the optics unit.

Table 2. Incorporated laser (CLT611 transmitter)
Property Value
Laser wavelength 910.55 nm
Peak power 50 W
Maximum average power 70 mW
Pulse duration 160 ns FWHM
Pulse frequency 9.5 kHz
Typical beam divergence ±7 degrees
Figure 1. Location of explanatory and certification labels on CL61. The device is equipped with the following labels:

Take the following precautions during installation, operation, and maintenance:

WARNING Viewing the laser output with telescopic optical instruments (for example, telescopes or binoculars) may pose an eye hazard. Do not direct the beam into an area where such instruments are likely to be used.
WARNING Only qualified maintenance personnel may perform maintenance procedures. Make sure unauthorized persons cannot access the work area during service operations.
WARNING Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.
Figure 2. Location of CL61 laser aperture
Laser aperture
Laser class 1M, direction of transmitted light
Laser class of the incorporated laser (transmitter module CLT611) is 3B.

The transmitter module has a laser aperture and label as shown in the following figure. Avoid exposure to the beam from the aperture.

WARNING Do not remove the transmitter module CLT611 from its normal position without first switching off the AC (mains) power.
WARNING Do not look at the transmitter module CLT611 of the ceilometer from the beam direction when the transmitter is powered.
Figure 3. Location of warning and explanatory labels on transmitter module CLT611
Laser aperture